Electric fuse.



A. P. BENDER.

ELECTRIC FUSE.

APPLICATION FILED DEC. 5. 1914.

1,290,860. Patented Jan. 7, 1919. 2 SHEETS-SHEET A. P. BENDER.

ELECTRIC FUSE.

APPLICATION FILED DEC. 5. 19m.

1,290,860. Patented Jan. 7, 1919.

. 2 SHEETS-SHEET 2- FIG. 9

WITNESSES. INVENTOR.

j- MM flaw W M A7 /Z7 25%;?

- CITED ES ATENToF I EQ ALLAN P, BENDEB, OF WILKINSBUBG, PENNSYLVANIA,ASSIGNOB. TO WESTINGHOUSE ELECTRIC & MANUFACTURING comm, A CORPORATIONOF PENNSYLVANIA. 1

To all whom it may concern:

Be it known that-I, ALLAiv P. BENDER, a

citizen of the United States, and resident of- Wilkinsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful. Improvement in Electric Fuses; and-I do hereby declare thefollowing to be a full, clear, and exact description thereof.

My invention relates to electric fuses One object of the invention is toprovide a self-contained cartridge in which the fuse element is mounted,which cartridge may be slipped into the ordinary fuse casing and lock'edtherein, Thiscartridgecontains the.

usual inert material for preventing destructive effects of arcing,betweenthe terminals of the broken fuse and to prevent transmission ofthecurrent through the gases of the fused material from reaching theterminals of the fuse member. A further 'object is to provide improvedmeans for positioning the fuse cartridge within the casing so that thesecuring caps may be readily slipped into lace; and a further ob ect isto improve t e securing caps to provide a lock for holding the fusecartridgg inthe casing in proper position. A furtherobject isto providemeans whereby the 'caps at the end of'the casing may be secured to thecasing without dependin upon screw threads in the fibrous material ofthe casing itself. Afurther object is to provide means. for determiningthe rating of the fuse without removing same from the casing. -Otherobjects and advantages of the invention will appear from the followingdescription taken in connection with the accompanying drawiings, whichillustrate preferred embodi ments of the invention, and inwhich Figure 1is a longitudinal sectional view of a fuseiembodying the invention; Fig.2 is a similar view takenvat right angles to Fig. 1; Fi 3 is an end viewshowing the casing cap in oaking position ;-ZF1g. 4 is an end viewshowing the casing in unlocked position Fig. 5 is an Specification ofLetters Patent f Application filed December 5, 1914. Serial No. 675,633.

' reduced central ELECTRIC FUSE.

FatentedJan. 7, 1919.

end view showing the cap removed; Fig. 6 is a perspective new of. thefuse cartridge adapted to be slipped withinthe fuse casing;

Fig. 7 is a fragmentary end view of the fuse 'casing showing certaindetails; Fign'S is a' perspective view of a holding and alining memberfor the fuse element and the casing cap; Fig. 9 is a view similar toFig.1 of a modified form of fuseelement; Fig. 10 is a transversesectional view on the line l010,

Fig. 9; Fig. 11 is'a. side elevation of the fuse element detached; Fig.12 is a view ofrthe' blank from which the fuse element, Fig. 11, isformed; and Fig. 13 is a longitudinal sectional view of a furthermodification.

In the embodiment of the invention illustrated in Figs. 1 to 6,inclusive, the fuse element'proper consists of a strip 1 of zinc orother suitable material, which may have a fusing operation This fuseelement is contained within a cartridgelike structure comprising thecylindrical body portion 3-and the fuse element may be surrounded witha,

packing 6 of comminuted plaster of Paris, whiting, asbestos or the liketo form a heat dissipating, flame quenching medium, which portion 2 tofacilitate the v will preyent damaging effects of arcing be tween theterminals of the broken fusememher, and will also prevent access ofgases "formed during the fusing operation from reaching theterminals ofthe circuit.

T0 the fuse member 1 may be attached the copper terminals 7-7 in anydesired manner, as by means of screws 88. The

complete self-contained fuse member and its cartridge is illustrated inper pective view Fig. 6. This cartridge may be slipped within theordinary fuse casing comprislngthe cylindrical casing body 9 and the endcaps 10. The casing 9 may be provided with an' aperture 9', and thecartrid e with a num .ber '3 indicating the rating of the fuse,

adapted to be in alinement with the aperture 9 so that said rating maybe determined without removing the cartridge from the casing. 'Inordinary practice, it is usual to thread the caps 10 and the ends of'thefuse casing 9 and screw the one upon the other. This is foundunsatisfactory since on account ofthe fibrous nature of the casing, thescrew threads thereon quickly wearndown and arestripped. I overcome thisdifficulty and' at the same time facilitate the proper alinement. of theterminals of the fuse member within thecasing by the following means.

Referring to Fig. 8, I provide a locking member consisting of, adisklike body portion 11- having'a slot 12 to receive the fuse terminals'7, said member 11 having opposite lugs 13 adapted to fit within notches14,

Fig. 7, of the fuse casing-9. Locking member 11 is also provided withthe lugs 15 at right angles thereto, each having-a threaded aperture 16.In assembling the fuse cartridge within the casing 9, the terminals 7are first secured to the projecting ends of the fuseelement 1, and thecartridge is then slipped into place within the casing 9. Thelocking.members 11 are then slipped over the terminals 7 and the lugs 13 areseated,

within the notches 14 of the casing. 'This 1 brings the threaded lugs 15into register with apertures 17 in the ends of the casing 9. It willbe'seen, therefore, that the ter- 'minals' 7 may thus be held in exactaline- 30 'the fuse cartridge and its terminals cen-' trally within thecasing 9, I provide the closment within the casing. In order to hold ingand locking caps 10, the ends of which are provided with elongated ovalopenings 18 of an extreme length slightly greater than the width of theterminal 7. These caps are slipped over the terminal. 7 and down intoplace upon the ends of the casing ,9.- As shown in 1, the opposite sideedges of the termlnals 7 are kerfed or notched as at 19so that when thecaps 10 are turned after being seated upon the ends of the casing, theedges at the narrowed portion of the opening 18lengage' these notches 19and lock the fuse terminals in position. The caps 10 are also perforatedas at 20, Fig. 2, to receive the locking screws 21,

j which pass through the apertures 17 of'the casing and engage in thethreaded apertures 16 of the lugs 15 of the locking member 11. Thus itwill be seen that by threading the screws 21 into the lugs 15, thelocking member 11, cap 10, and easing are securely fastened together,with the ends of the ,fiber' casing simply clamped between the flange ofthe cap 10 and the lugs 15; and it will be seen further, that thefastening of the caps 10 on the casing does not depend upon threadsformed in the fibrous material of the casing.

' In the embodiment of the invention illus 'trated in Figs. 9 to 12,inclusive, all parts are as heretofore described with. the exception ofthe fuse element proper. In. this" case, I have found that by formingthe'fuse element intermediate its ends in hollow form of so-calledexpanded metal, I may use a very much thinner'material for the fuseelement, and obtain better distribution of the fusible substance. Inthis case, referring to Fig. 12, the fuse element is formed of a blank22 of very thin fusible material.

This blank is provided-with a number of parallel staggered cuts 23, andif desired, certain of these cuts may include apertures 24. The blank soprepared may then be folded upon itself and the central part expanded asindicated in Fig. 11 formin a cylindrical central body portion withattened ends, said flattened ends beinglapertured as at 25 to receivethe terminal attaching screws 8. i

In the embodiment of the invention as illustrated in Fig. 13, the parts,in the main, may be as heretofore descrlbed, but the manner of attachingthe terminals 7 is modified in that I employ flexible connections 26be-' tween the fuse member land said terminals 7 .The terminals 7 eachconsist of flat body portion 7 having lateral projections 7 3 at theouter end thereof. The cap 10 in this case, may be as-heretoforedescribed,

scope of the appended claims.

' WhatI claim is:

1. An electric fuse comprising a fuse casing, a fuse element mountedtherein and-havingthe usual' terminals, locking members adapted to heslipped over the said termi- "nals, and having means to hold said terminals in alinement within said'casing, a cap adapted to' be slipped oversaid terminals and seated upon the ends of said casing, said cap havingself-contained meansto lock the fuse element within said casing, andauxiliary locking means to lock said cap, looking member, and casingtogether.

2. An electric fuse comprising a fuse casing, a fuse element mountedtherein and having the usual terminals, locking members adapted to beslipped over the said terminals, and having means to hold said terminalsin alinement within said casing, caps adapted to be slipped over saidterminals and seated uponthe ends of said casing, said caps each havingmeans to lock the fuse element within said casing, said locking memberseach having threaded lugs extending In testimony whereof, I the saidALLAN along the inner Wall of said cgsing, and said P. BENDER, havehereunto set my hand. ca having apertures in its ange Whereb said canand locking member and said eas ALLAN BENDER' 5 ing may be securedtogether by means of Witnesse's:

screws passing through said cap-flange, c'as- JOHN F. WILL, ing Wall andthreaded into said lugs. J. R KiELLER.

